Students will be able to:
- investigate the effects of construction and other human activity on beaches.
Virginia Standards of Learning:
- ES.10: The student will investigate and understand that oceans are complex, interactive physical, chemical, and biological systems and are subject to long- and short-term variations. Key concepts include:
- physical and chemical changes related to tides, waves, currents, sea level and ice cap variations, upwelling, and salinity variations;
- importance of environmental and geologic implications;
- systems interactions;
- features of the sea floor as reflections of tectonic processes; and
- economic and public policy issues concerning the oceans and the coastal zone including the Chesapeake Bay.
Human activities can have a significant impact on coastlines. Often, humans will build ocean features along coastlines that will have an impact on longshore currents. Some of those features include groins, jetties, breakwaters and seawalls.
Groins are artificial protrusions sticking out into the ocean perpendicular to the shore. Groins are built to create an area relatively protected from longshore current often for recreation such as fishing. Groins are built from piles of boulders and stone usually, sometimes with sand bags, concrete and other materials.
A jetty in Namibia
Jetties are built with much the same material as groins as well as under the same idea as groins. However, jetties are most often built to reinforce a harbor entrance.
Breakwaters are man-made structures parallel to the shore or curving slightly out into the ocean. The purpose of breakwaters is to create an artificial lagoon to use as a harbor or beach.
Seawalls are walls built to protect development along the coastline. Many resorts worldwide are protected by seawalls to help prevent the resort from experiencing the impact of the ocean, especially in times of severe weather.
A seawall in Vancouver
Each of the above mentioned structures have an impact on sand movement. Naturally, longshore currents move and shift sands along coastlines. However, when humans build structures protruding out into the ocean capturing sand on one side of the protrusion, the other side of the protrusion will eventually erode away because there is no sand being deposited down current from the protrusion. There are definitely positives and negatives to each of these structures. As with many environmental activities, humans often work with nature to balance human needs as well as environmental impact. As time progresses, coastal attitudes and management will remain important parts of environmental policies regarding coastal communities.
Use the information in the lesson to complete the following ungraded activity:
Pretend you live in a coastal community. A major industry in this coastal community is tourism. Another major industry is fishing. A majority of the individuals who live in your coastal community, including yourself, work in either the tourism industry or fishing industry for their livelihood. A local government official has recently proposed a series of jetties, groins, and seawalls along the coast in your community. Given the information above, offer support or decline support for the local government official’s proposal by answering the following questions in an article:
- Why do you or do you not support your local official’s proposal?
- What would be the benefits of this proposal?
- What would be the downfall of this proposal?
- What do you value as the most important parts of this proposal?
- Why do you feel the way you do?
The minimum length for this assignment is 3 paragraphs.
Note: This lesson also includes an ungraded introductory quiz and a graded summative quiz. Students will complete those quizzes—and submit their response to the assessment described above—within the Virtual Virginia LMS, Canvas.
- Objectives: Earth Science Standards of Learning, Virginia Department of Education. http://www.doe.virginia.gov/testing/sol/standards_docs/science.
- “Hurricane damage | Natural Disasters: Hurricanes, Tsunamis, Earthquakes.” eMedia. https://emediava.org/lo/1000065550.
- “Mole, Jetty and Lighthouse of Swakopmund in Namibia.” Olga Ernst [CC BY-SA], via Wikimedia Commons.
- “Seawall Vancouver.” Kaveh [CC BY-SA 2.0], via Wikimedia Commons.